1. Field of the Invention
The present invention relates to a method for producing optically active N-(2-acetylthiomethyl-1-oxo-3-phenylpropyl)-amino acid ester. The present invention is useful for producing optically active N-(2-acetylthiomethyl-1-oxo-3-phenylpropyl)-glycine benzyl ester.
2. Description of the Related Art
(S)-N-(2-acetylthiomethyl-1-oxo-3-phenylpropyl)-glycine benzyl ester with an inhibitory action against angiotensin converting enzyme is useful as therapeutic agents of deteriorated cardiovascular system, hypertension, cardiac function impairment and liver function impairment. Alternatively, the (R) form thereof with an inhibitory action of enkephalinase is useful as analgesic, antidiarrheic, and antacid (JP-A-2-161 and JP-A-8-59606). Methods for producing optically active N-(2-acetylthiomethyl-1-oxo-3-phenylpropyl)-glycine benzyl ester having been known so far include a method comprising optically resolving racemic 2-acetylthiomethyl-3-phenylpropionic acid by using ephedrine and subjecting one of the resulting products to condensation with glycine benzyl ester and N, N'-dicyclohexylcarbodiimide (JP-A-8-59606). According to the method, however, the efficiency of the optical resolution of 2-acetylthiomethyl-3-phenylpropionic acid with ephedrine is so low that the method is not practical. Furthermore, the method generates such an enormous volume of sulfur-containing wastes that the method cannot be said to be an industrially advantageous method.